Folic acid sparks debate among scientists

SMC Alert
18/05/09
IMMEDIATE RELEASE

Science Media Centre
smc@sciencemediacentre.co.nz

Folic acid sparks debate among scientists

Concerns have been expressed about the possible negative effects of folic acid fortification, especially for those who are deficient in vitamin B12. An article in the Herald on Sunday yesterday highlights concerns about this standard.

Here in New Zealand, the standard was passed recently requiring all bread manufacturers to fortify bread with folic acid by September 2009. More information can be found on the Food Standards Australia New Zealand (FSANZ) website.

Folate is a B vitamin found naturally in foods such as leafy vegetables, dried peas and beans, bananas and oranges. Folic acid is the synthetic form of the vitamin, which may be added to manufactured foods and drinks, or may be taken as a vitamin supplement.

Women who have inadequate intakes of folate in the early stages of pregnancy are at increased risk of having a baby with a neural tube defect, and as such it is recommended that pregnant women take a folate supplement when planning to conceive and during the first 12 weeks of pregnancy.

Mandatory fortification of enriched breads, cereals, flour and other grain products has taken place the USA, for some years and has resulted in a 25% drop in the rate of neural tube defects. Further, a paper published in the BMJ last week found that in Canada, public health measures to increase folic acid intake were followed by a decrease in the birth prevalence of severe congenital heart defects.

We asked some New Zealand experts about their view on mandatory folic acid fortification and whether they had any concerns about possible adverse effects.

Elaine Rush is Professor of Nutrition at Auckland University of Technology. She comments:

"The fortification of food with folic acid will help prevent neural tube defect in babies and has the potential to lower plasma homocysteine, which is a risk factor for vascular disease. However, vitamin B12 is also an important factor in the prevention of neural tube defect as well as in the reduction of plasma homocysteine. Folic acid will mask vitamin B12 deficiency. Vitamin B12 is only found in foods of animal origin

"Those at risk of vitamin B12 deficiency in New Zealand include the elderly and those who do not eat meat such as vegetarian Indians, an increasing number of young girls, and people who believe that plant foods are more sustainable for the planet. With the recession, those who cannot afford the more expensive meat and dairy foods will eat more plant foods. New Zealand (unlike Australia) does not allow vitamin B12 to be added to cereals.

"There is evidence from India that maternal low B12 and high folate status are related to intrauterine growth retardation, and also with adiposity, insulin resistance and poor neuro-cognitive performance during childhood. We have measured pre-adolescent Indian girls and adults here in New Zealand, and B12 is also a problem for them.

"In isolation, the addition of single nutrients to a food supply may cause other unintended effects and the issue of fortification does need thinking though carefully so that all the population groups in New Zealand benefit".

Jan Milne is Executive Director of the New Zealand Dietetic Association. She comments:

"The New Zealand Dietetic Association's preferred option throughout the consultation process with Food Standards Australia New Zealand was the continuation of voluntary folic acid fortification in foods in combination with increased education to women of childbearing age about the role of folic acid in reducing the risks of neural tube defects.

"NZDA is concerned that the success of the mandatory fortification process relies on women of child bearing age continuing to take a folic acid supplements. In relation to this, NZDA is concerned that the dose of the folic acid supplement that is available to women has not been altered to take account of the change in folate and folic acid available in the food supply as a result of mandatory fortification"

Dr Claire Wall is a senior lecturer in nutrition from the University of Auckland. She comments:

"I am supportive of mandatory folic acid fortification in New Zealand, there are likely to be significant benefits in terms of reducing neural tube defects and no adverse effects have been reported in the USA where there has been mandatory fortification of folic acid for several years.

"At a population level, the proposed amount of of folic acid that will be added is very safe, and will not increase the risk of cancer."

Lydia Buchtmann is spokesperson for Food Standards Australia New Zealand. She comments:

"There have been many years of research on the issue of folic acid fortification. We have concluded that at the levels we are proposing to add folic acid it will be perfectly safe for the general population and will greatly reduce the risk of neural tube defects.

"Mandatory fortification of folic acid has taken place in the USA for over 12 years and during this period neural tube defects have been reduced and there is no other evidence of ill health.

There is very strong evidence for the safety of folic acid, but there will be ongoing monitoring to ensure that fortification continues to be a safe and effective practice."

Notes to Editors
The Science Media Centre (SMC) is an independent source of expert comment and information for journalists covering science and technology in New Zealand. Our aim is to promote accurate, bias-free reporting on science and technology by helping the media work more closely with the scientific community. The SMC is an independent centre established by the Royal Society of New Zealand with funding from the Ministry of Research, Science and Technology. The views expressed in this Science Alert are those of the individuals and organisations indicated and do not reflect the views of the SMC or its employees. For further information about the centre, or to offer feedback, please email us at smc@sciencemediacentre.co.nz.

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